1. Field of the Invention
This invention relates to vehicular audio systems in which a headliner includes electromagnetic transducer assemblies for driving a sound radiating lower surface of the headliner with covers protecting the transducers.
2. Background Art
Audio systems continue to be developed for improving the utility and sound quality of communication systems and audio systems in a vehicle. Although distribution of a transducers emanating the sounds has been accomplished in many ways, traditional transducers in which the voice coil in a magnetic field moves a diaphragm integrally formed with the speaker in a framed construction, are not readily adapted to be housed in the headliner area because of their size and weight. As a result, many audio systems avoid placement of transducers in the headliner despite the close proximity of the headliner to the ears of passengers in the vehicle.
A previously known headliner construction for including transducers in the headliner is defined in U.S. patent application Ser. No. 09/121,788 in which the transducers are specially constructed audio speakers, for example thin speakers known as “Active Screen Speakers” manufactured by American Power and Light of Plymouth, California having a screen against which visual images may be projected. The headliner is manufactured with the speakers compression molded between material layers of the headliner. However, the sandwiching technique limits the use of these speakers to original equipment manufacturing production processes, and does not permit headliners to be retrofit with special purpose audio accessories or systems. Moreover, such constructions limit the types of speakers that may be employed with the headliner.
Another known vehicle audio system of U.S. patent application Ser. No. 09/382,851 discloses a vehicle audio system in which transducers are designed to interact with a sound emanating layer of the headliner and avoid the need for traditional cone diaphragms or the like. However, such transducers extend up above the headliner, and are exposed to dust and inadvertent contact with the environment during handling, assembly and production of the vehicle. Such exposure can adversely affect the performance of the speakers after vehicle assembly.